Modifying Bühler replacement motor for LGB 2085D Mallet Locomotive

[Gavin Kistner]

I inherited a lovely LGB set from my father, including a 2085D Mallet locomotive he purchased circa 1980. The rear motor on the locomotive died a couple years ago. (Taking it out and pumping high voltage and current through it causes it to turn fitfully, requiring far more DC than it ought to, and smoke (!).) I bought a replacement locomotive at the time, and am now getting around to trying to fix the 2085D.

I purchased a replacement motor and just went to swap it out…and it's not quite right. It's still a Bühler motor, and the body and shaft lengths match, but the motor does not fit correctly in the plastic; the "bumps" on the ends of the motor are 0.5mm and 1.1mm too long, and one of the bumps is just a little bit too wide (unsure if this is an issue). And, the metallic contacts are not in the same spots.

Photos and comparisons follow. My question is: have other people experienced this? Did I buy the wrong motor, or is 40 years too long to get a perfect replacement? I'm hoping I can file down the motor bumps to fit; have you done this? If necessary after I get it physically in place I may have to solder in a very short jumper wire to make the electrical connection.

 

[muns]

There should be a plastic addition (that acts as the alignment pin) loose in the packet with the motor.

 

[Gavin Kistner]

There should be a plastic addition (that acts as the alignment pin) loose in the packet with the motor.

That's helpful at least, thanks!
On another forum they say that it's a known issue that the motors are too long, and I have to mill/lathe/grind them down.

 

[Paul M]

Welcome to the forum Gavin. You've made a good start with your pictures. Pictures say a 1000 words.

 

[Dan]

Yes, the alignment piece with the pin is missing and should have come with the new motor.